The present disclosure relates generally to optical fiber component testing and, more particularly, to an apparatus and method for in-situ vibration testing of fiber optic cables and connectors.
Entities presently engaged in the manufacture and use of communication systems (e.g., voice, video and/or data communication), have become increasingly interested in using fiber optic cables as transmission media in such systems. This interest is stimulated in part by the fact that the potential bandwidth (i.e., information-carrying capacity) of optical fibers is extremely high. In addition, communication systems employing fiber optic cables are resistant to electromagnetic interference, which sometimes plagues systems employing electrical cables as transmission media. Moreover, communication systems employing fiber optic cables are generally considered more secure than systems employing electrical cables because it is typically more difficult for unauthorized personnel to tap or access a fiber optic cable without being detected.
As is the case with electrical cable, connector technology is also an important aspect of fiber optic communication systems. For example, conventional duplex fiber optic connectors (such as SC Duplex connectors) provide for the alignment of optical fibers by threading each fiber through a precision ceramic ferrule. The two ferrules of an SC connector have an outer diameter of about 2.5 millimeters (mm), and the resulting fiber-to-fiber spacing (or pitch) of a duplex connector is approximately 12.5 mm. Since the outer of the fiber captured by the ferrule is only about 125 microns (xcexcm), it is possible to design a significantly smaller optical connector having fewer precision parts in order to reduce manufacturing costs.
Recently, a new class of small form factor (SFF) fiber optic connectors has been introduced with the goal of reducing the size of a fiber optic connector to one half of that of a standard SC Duplex connector while maintaining or reducing the cost. Several different designs have been proposed by different manufacturers, including the SC-DC or SC-QC (by IBM and Siecor), the LC (manufactured by Lucent Technologies and others), the MT-RJ (manufactured by Fujikura, Siecor and AMP and others), and VF-45.
A communication system employing fiber optic cables, connectors, electro-optic modules and other associated components can only operate effectively if the components are in conformity with corresponding operating specifications. Qualification testing is thus implemented to determine whether the various components conform to their respective specifications, as well as to detect and correct errors in manufacturing processes which lead to any non-conformities in the components. In particular, a part of the qualification testing of SFF fiber optic connectors includes vibration testing for determining the connector robustness in high reliability applications.
Under existing IBM and Bellcore standards, vibration testing is presently implemented for SFF fiber optic connectors on an individual basis using a series of set parameters. These parameters, which include both random and operating vibration, involve plugging and cycling each connector individually through a series of tests lasting from about 15 minutes to about 1 hour per test axis. As with any qualification test procedure, however, those engaged in the development and manufacture of fiber optic communication systems have long sought systems and methods for testing components which require relatively short testing times and which also better simulate actual system performance.
The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by an apparatus for performing vibration testing of fiber optic components. In an exemplary embodiment, the apparatus includes a base member and a mounting assembly for holding a plurality of connectors therein, The plurality of connectors optically couple a plurality of fiber optic cables with one another in a serial configuration. In addition, a securing mechanism adjustably secures the mounting assembly in a selected axial orientation with respect to the base member, wherein the mounting assembly allows simultaneous vibration testing of each of the plurality of connectors.
In one embodiment, the mounting assembly further includes a generally planar sheet member, a flange member extending from the sheet member, and an optical coupling assembly inserted within the sheet member. The optical coupling assembly secures the plurality of connectors therein. An input device is used for transmitting a test signal through the fiber optic cables and the plurality of connectors, while an output measuring device is used for measuring the transmitted test signal. The output measuring device is preferably capable of displaying a localized, visual output of the transmitted test signal.
In a preferred embodiment, the input device includes a pattern generator configured as a bit error rate tester, and the output measuring device further includes a digital sampling oscilloscope. A plurality of optical couplers is configured within the optical coupling assembly, each of the plurality of optical couplers providing optical coupling between a given pair of connectors.